("Clap Along" by Dave Pepper)
- My name is Nivedita Nagaraj, and the title of my poster
was "Oxidation Pathways
in Ultra-High-Molecular-Weight Polyethylene:
A Comprehensive Explanation
of Joint Arthroplasty Degradataion."
Yep, that's a long title.
So, the focus of my project was exploring
the oxidative degradation of polyethylene materials
used in knee replacements.
So, our study aimed to establish a mechanistic base model
of in vivo oxidation for polyethylene materials
that do not have an existing free radical concentration.
So, historically, polyethylene oxidation was attributed
to irradiation-induced free radicals, but later
they developed materials
that eliminated these free radicals.
But recent reports have showed that these materials
are still oxidizing, so, basically, my study looked
at trying to find an explanation for why these materials
that do not have a free radical concentration
are oxidizing in the body.
So, we were able to identify
three free radical generating mechanisms
that came from three different sources:
irradiation, lipids, and reactive oxygen species
present in the synovial fluid.
And these three mechanisms ultimately converged
into a single free radical-based oxidation mechanism,
and this led to increased wear generation
and an overall degradation of mechanical properties.
("Clap Along" by Dave Pepper)
So, my greatest challenge was developing the GC-MS,
so gas chromatography-mass spectrometry protocol
to identify the organic content in polyethylene materials
that were taken from patients' bodies
because they had failed previously.
So, I had to, I went through a number
of different challenges, from contamination
with the lipids and the fatty acids
and also equipment malfunctions, wear/break problems.
So navigating these challenges took almost a term,
and it usually meant that I had
to start over multiple times, but eventually I was able
to develop a protocol that was able to successfully identify
the organic content in these materials that had come
from patients' bodies, and we found that lipids
and sterols and hydrocarbons were diffusing
from the synovial fluid into the polyethylene material
and could initiate oxidation.
And that led to the creation
of the lipid peroxidation mechanism.
("Clap Along" by Dave Pepper)
So, I've worked over at Thayer,
at the Dartmouth Biomedical Engineering Center,
since I was a freshman as a WISP student.
So I've been there for quite a while,
and it's been a great experience.
My mentors and my thesis advisors,
Douglas Van Citters and Barbara Currier,
have supported me and guided me
throughout this entire process, and there've always been
super supportive, pushing me with the hard questions
and challenging me to think really critically
about my project.
So that was a awesome experience.
And then I also, through this project, had the opportunity
to work over at the chemistry department
with Catherine Welder and Charlie Ciambra.
So that was exciting, because I got to,
through their guidance, I was able to use lab techniques
that I learned in orgo with Dr. Welder
and actually apply them to real-life research,
so seeing that was really exciting.
And I think, just in general, this experience taught me
that collaborating across sciences and across disciplines
can be really an important tool in solving many problems.
("Clap Along" by Dave Pepper)
For me, library research was a constant process
throughout my senior thesis, from the beginning to the end.
The most important resources were the databases,
having access to journals like Polymer and Biomaterials
were critical to the success of my project.
And I also, so, most of my research was in engineering
and orthopedics, but I had to step into the chemistry world
and use the chemistry databases in order to look
at different types of oxidation mechanisms,
peroxide decomposition mechanisms that occurred
whether in chemistry labs or people had identified them
in an atmosphere, or in, like, other environments,
and seeing if those mechanisms can be applied
to polyethylene oxidation.
So the library resources were incredibly important
for that process.
("Clap Along" by Dave Pepper)
Next year, I'll be working in Boston
as a healthcare consultant, so I get the chance
to combine my interest in science, but also my interest
in business and healthcare strategy.
So that I'm thinking about doing for about one
to two years, and then hopefully going on to medical school
and getting and MD or an MD/MBA.
("Clap Along" by Dave Pepper)